Methods

Patients' sera were evaluated at baseline, after 12 weeks (ws), 48 ws and at the last available time point (at recurrence/remission) (observation arm, n = 488; vaccination arm, n = 471) for the presence of serum antibody responses against a panel of 45 antigens by a bead-based multiplex serological assay.

Results

We frequently observed serum antibodies against all tested antigens in all patients except for 22 patients, who did not have any antibody responses at all (Table 1). 52 patients had antibodies against only one antigen, whereas most patients showed antibody responses against multiple antigens. By trend, we could confirm our previous findings of spontaneous antibody responses being associated with shorter PFS and OS. A negative prognostic value was depicted for a panel of IgG antibodies at baseline against Rhod E2, CyclinB1 for OS and Rhod E2, SSX2 for PFS in a multivariate analysis (adjusted for gender, Breslow thickness, ulceration status).

Conclusions

The serum profiling of antibody responses against a panel of TAA will help to identify patients of dismal prognosis who may benefit from an adjuvant immunotherapy. The sequential evaluation of humoral immune responses at the available time points as well as analysing their predictive impact is planned.
Table 1:

Frequency of antibody responses against a panel of 45 antigens in patients of the EORTC18961 trial